Unable connect Windows 10 to Mikrotik L2TP/IPsec behind NAT – Solved

Open regedit (Windows + R -> regedit -> enter) find key : Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\PolicyAgent. Create new DWORD value with name : AssumeUDPEncapsulationContextOnSendRule and value 2 Restart PC and enjoy the L2TP/IPsec without problems.